Radio head: Short Cuts - Ruby Baby

Short Cuts: Ruby Baby (BBC Radio 7) embraces a novel dramatic format. Louisa Young has penned a two-part thriller set in an organic Tuscan vineyard where a group of students are working as summer volunteers. It is, I should add, far less annoying than that description makes it sound. Between the two instalments – the first was broadcast on Monday, the second follows a week later – six young writers have responded with their own two-minute plays, speculating on what might have happened to Ruby, who goes missing on a night out.

It's rather good. The short plays are little more than moments, really, dripping with dramatic intensity. Yesterday's, by Indiana Seresin, focused on two of the party searching for Ruby in a dank cellar and managed, in this blink-and-miss-it sliver, to convey a real sense of foreboding. "This feels like a maze," says Sarah, terrified of the dark. "You city girls, always so jumpy," her colleague replies, ignoring the fact that they are in the grounds of a creepy castle, in total darkness, with one of their party already missing, amid talk of bandits and wild animals, and the memory of a gunshot heard earlier in the night.

Young's half-hour initial play has to do most of the work, establishing characters and dropping hints of something not quite right, and it is instantly gripping. There are peculiar outbursts ("You don't feed someone else's dog at table," the castle owner snaps at Ruby) and curious rituals: whenever they toast a drink, everyone has to stare into the eyes of everyone else in turn.

The shorter plays are like a welcome conversation with the main plot, amplifying and heightening elements of it. Heard in isolation they might sound very silly, but after the opener, they are tense reminders of it, underlining the menace and mystery. Obviously the thriller genre lends itself to this experimental format: the tiny plays each evening drip ominous clues and chilling reminders until the final denouement.